There frequently exists a need to create connections to rigid enclosures such as process equipment and piping so that access to the enclosures can be provided. In many cases such enclosures are fabricated of steel and connections are welded to the equipment and piping. However, in certain circumstances welding is undesirable for either metallurgical or plant operations reasons. One means of creating a non-welded connection is by the use of a bolted on assembly, also referred to as a “tapping sleeve,” which is placed around the outside of a pipe or other circular equipment, e.g., a pressure vessel. This type of external connection can often be excessively heavy as to be impractical. Furthermore, internal pressure from within the enclosure tends to apply force on the clamped on device which can tend to separate the device from the enclosure and weaken the repair over time. In such cases, a supplemental “strong back” device may be necessary to hold the device in place.
Thus a mechanical means of creating a pressure tight connection by which an enclosure could be accessed would be desirable.